4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 * Jeremy Allison (jra@samba.org) 2006.
8 * This library is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU Lesser General Public License as published
10 * by the Free Software Foundation; either version 2.1 of the License, or
11 * (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
16 * the GNU Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public License
19 * along with this library; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <linux/list.h>
25 #include <linux/gfp.h>
26 #include <linux/wait.h>
27 #include <linux/net.h>
28 #include <linux/delay.h>
29 #include <linux/freezer.h>
30 #include <linux/tcp.h>
31 #include <linux/bvec.h>
32 #include <linux/highmem.h>
33 #include <linux/uaccess.h>
34 #include <asm/processor.h>
35 #include <linux/mempool.h>
36 #include <linux/sched/signal.h>
39 #include "cifsproto.h"
40 #include "cifs_debug.h"
41 #include "smb2proto.h"
42 #include "smbdirect.h"
44 /* Max number of iovectors we can use off the stack when sending requests. */
45 #define CIFS_MAX_IOV_SIZE 8
48 cifs_wake_up_task(struct mid_q_entry *mid)
50 wake_up_process(mid->callback_data);
54 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
56 struct mid_q_entry *temp;
59 cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
63 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
64 memset(temp, 0, sizeof(struct mid_q_entry));
65 kref_init(&temp->refcount);
66 temp->mid = get_mid(smb_buffer);
67 temp->pid = current->pid;
68 temp->command = cpu_to_le16(smb_buffer->Command);
69 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
70 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
71 /* when mid allocated can be before when sent */
72 temp->when_alloc = jiffies;
73 temp->server = server;
76 * The default is for the mid to be synchronous, so the
77 * default callback just wakes up the current task.
79 get_task_struct(current);
80 temp->creator = current;
81 temp->callback = cifs_wake_up_task;
82 temp->callback_data = current;
84 atomic_inc(&midCount);
85 temp->mid_state = MID_REQUEST_ALLOCATED;
89 static void _cifs_mid_q_entry_release(struct kref *refcount)
91 struct mid_q_entry *midEntry =
92 container_of(refcount, struct mid_q_entry, refcount);
93 #ifdef CONFIG_CIFS_STATS2
94 __le16 command = midEntry->server->vals->lock_cmd;
95 __u16 smb_cmd = le16_to_cpu(midEntry->command);
97 unsigned long roundtrip_time;
99 struct TCP_Server_Info *server = midEntry->server;
101 if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) &&
102 midEntry->mid_state == MID_RESPONSE_RECEIVED &&
103 server->ops->handle_cancelled_mid)
104 server->ops->handle_cancelled_mid(midEntry, server);
106 midEntry->mid_state = MID_FREE;
107 atomic_dec(&midCount);
108 if (midEntry->large_buf)
109 cifs_buf_release(midEntry->resp_buf);
111 cifs_small_buf_release(midEntry->resp_buf);
112 #ifdef CONFIG_CIFS_STATS2
114 if (now < midEntry->when_alloc)
115 cifs_server_dbg(VFS, "Invalid mid allocation time\n");
116 roundtrip_time = now - midEntry->when_alloc;
118 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) {
119 if (atomic_read(&server->num_cmds[smb_cmd]) == 0) {
120 server->slowest_cmd[smb_cmd] = roundtrip_time;
121 server->fastest_cmd[smb_cmd] = roundtrip_time;
123 if (server->slowest_cmd[smb_cmd] < roundtrip_time)
124 server->slowest_cmd[smb_cmd] = roundtrip_time;
125 else if (server->fastest_cmd[smb_cmd] > roundtrip_time)
126 server->fastest_cmd[smb_cmd] = roundtrip_time;
128 cifs_stats_inc(&server->num_cmds[smb_cmd]);
129 server->time_per_cmd[smb_cmd] += roundtrip_time;
132 * commands taking longer than one second (default) can be indications
133 * that something is wrong, unless it is quite a slow link or a very
134 * busy server. Note that this calc is unlikely or impossible to wrap
135 * as long as slow_rsp_threshold is not set way above recommended max
136 * value (32767 ie 9 hours) and is generally harmless even if wrong
137 * since only affects debug counters - so leaving the calc as simple
138 * comparison rather than doing multiple conversions and overflow
141 if ((slow_rsp_threshold != 0) &&
142 time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
143 (midEntry->command != command)) {
145 * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
146 * NB: le16_to_cpu returns unsigned so can not be negative below
148 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS)
149 cifs_stats_inc(&server->smb2slowcmd[smb_cmd]);
151 trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid,
152 midEntry->when_sent, midEntry->when_received);
153 if (cifsFYI & CIFS_TIMER) {
154 pr_debug("slow rsp: cmd %d mid %llu",
155 midEntry->command, midEntry->mid);
156 cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n",
157 now - midEntry->when_alloc,
158 now - midEntry->when_sent,
159 now - midEntry->when_received);
163 put_task_struct(midEntry->creator);
165 mempool_free(midEntry, cifs_mid_poolp);
168 void cifs_mid_q_entry_release(struct mid_q_entry *midEntry)
170 spin_lock(&GlobalMid_Lock);
171 kref_put(&midEntry->refcount, _cifs_mid_q_entry_release);
172 spin_unlock(&GlobalMid_Lock);
175 void DeleteMidQEntry(struct mid_q_entry *midEntry)
177 cifs_mid_q_entry_release(midEntry);
181 cifs_delete_mid(struct mid_q_entry *mid)
183 spin_lock(&GlobalMid_Lock);
184 if (!(mid->mid_flags & MID_DELETED)) {
185 list_del_init(&mid->qhead);
186 mid->mid_flags |= MID_DELETED;
188 spin_unlock(&GlobalMid_Lock);
190 DeleteMidQEntry(mid);
194 * smb_send_kvec - send an array of kvecs to the server
195 * @server: Server to send the data to
196 * @smb_msg: Message to send
197 * @sent: amount of data sent on socket is stored here
199 * Our basic "send data to server" function. Should be called with srv_mutex
200 * held. The caller is responsible for handling the results.
203 smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
208 struct socket *ssocket = server->ssocket;
212 smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
213 smb_msg->msg_namelen = sizeof(struct sockaddr);
214 smb_msg->msg_control = NULL;
215 smb_msg->msg_controllen = 0;
216 if (server->noblocksnd)
217 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
219 smb_msg->msg_flags = MSG_NOSIGNAL;
221 while (msg_data_left(smb_msg)) {
223 * If blocking send, we try 3 times, since each can block
224 * for 5 seconds. For nonblocking we have to try more
225 * but wait increasing amounts of time allowing time for
226 * socket to clear. The overall time we wait in either
227 * case to send on the socket is about 15 seconds.
228 * Similarly we wait for 15 seconds for a response from
229 * the server in SendReceive[2] for the server to send
230 * a response back for most types of requests (except
231 * SMB Write past end of file which can be slow, and
232 * blocking lock operations). NFS waits slightly longer
233 * than CIFS, but this can make it take longer for
234 * nonresponsive servers to be detected and 15 seconds
235 * is more than enough time for modern networks to
236 * send a packet. In most cases if we fail to send
237 * after the retries we will kill the socket and
238 * reconnect which may clear the network problem.
240 rc = sock_sendmsg(ssocket, smb_msg);
244 (!server->noblocksnd && (retries > 2))) {
245 cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
249 msleep(1 << retries);
257 /* should never happen, letting socket clear before
258 retrying is our only obvious option here */
259 cifs_server_dbg(VFS, "tcp sent no data\n");
264 /* send was at least partially successful */
266 retries = 0; /* in case we get ENOSPC on the next send */
272 smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
277 unsigned long buflen = 0;
279 if (server->vals->header_preamble_size == 0 &&
280 rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) {
281 iov = &rqst->rq_iov[1];
282 nvec = rqst->rq_nvec - 1;
285 nvec = rqst->rq_nvec;
288 /* total up iov array first */
289 for (i = 0; i < nvec; i++)
290 buflen += iov[i].iov_len;
293 * Add in the page array if there is one. The caller needs to make
294 * sure rq_offset and rq_tailsz are set correctly. If a buffer of
295 * multiple pages ends at page boundary, rq_tailsz needs to be set to
298 if (rqst->rq_npages) {
299 if (rqst->rq_npages == 1)
300 buflen += rqst->rq_tailsz;
303 * If there is more than one page, calculate the
304 * buffer length based on rq_offset and rq_tailsz
306 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
308 buflen += rqst->rq_tailsz;
316 __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
317 struct smb_rqst *rqst)
322 unsigned int send_length = 0;
324 sigset_t mask, oldmask;
325 size_t total_len = 0, sent, size;
326 struct socket *ssocket = server->ssocket;
327 struct msghdr smb_msg;
328 __be32 rfc1002_marker;
330 if (cifs_rdma_enabled(server)) {
331 /* return -EAGAIN when connecting or reconnecting */
333 if (server->smbd_conn)
334 rc = smbd_send(server, num_rqst, rqst);
341 if (fatal_signal_pending(current)) {
342 cifs_dbg(FYI, "signal pending before send request\n");
346 /* cork the socket */
347 tcp_sock_set_cork(ssocket->sk, true);
349 for (j = 0; j < num_rqst; j++)
350 send_length += smb_rqst_len(server, &rqst[j]);
351 rfc1002_marker = cpu_to_be32(send_length);
354 * We should not allow signals to interrupt the network send because
355 * any partial send will cause session reconnects thus increasing
356 * latency of system calls and overload a server with unnecessary
361 sigprocmask(SIG_BLOCK, &mask, &oldmask);
363 /* Generate a rfc1002 marker for SMB2+ */
364 if (server->vals->header_preamble_size == 0) {
366 .iov_base = &rfc1002_marker,
369 iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
370 rc = smb_send_kvec(server, &smb_msg, &sent);
378 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
380 for (j = 0; j < num_rqst; j++) {
381 iov = rqst[j].rq_iov;
382 n_vec = rqst[j].rq_nvec;
385 for (i = 0; i < n_vec; i++) {
386 dump_smb(iov[i].iov_base, iov[i].iov_len);
387 size += iov[i].iov_len;
390 iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
392 rc = smb_send_kvec(server, &smb_msg, &sent);
398 /* now walk the page array and send each page in it */
399 for (i = 0; i < rqst[j].rq_npages; i++) {
402 bvec.bv_page = rqst[j].rq_pages[i];
403 rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
406 iov_iter_bvec(&smb_msg.msg_iter, WRITE,
407 &bvec, 1, bvec.bv_len);
408 rc = smb_send_kvec(server, &smb_msg, &sent);
417 sigprocmask(SIG_SETMASK, &oldmask, NULL);
420 * If signal is pending but we have already sent the whole packet to
421 * the server we need to return success status to allow a corresponding
422 * mid entry to be kept in the pending requests queue thus allowing
423 * to handle responses from the server by the client.
425 * If only part of the packet has been sent there is no need to hide
426 * interrupt because the session will be reconnected anyway, so there
427 * won't be any response from the server to handle.
430 if (signal_pending(current) && (total_len != send_length)) {
431 cifs_dbg(FYI, "signal is pending after attempt to send\n");
436 tcp_sock_set_cork(ssocket->sk, false);
438 if ((total_len > 0) && (total_len != send_length)) {
439 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
440 send_length, total_len);
442 * If we have only sent part of an SMB then the next SMB could
443 * be taken as the remainder of this one. We need to kill the
444 * socket so the server throws away the partial SMB
446 server->tcpStatus = CifsNeedReconnect;
447 trace_smb3_partial_send_reconnect(server->CurrentMid,
448 server->conn_id, server->hostname);
451 if (rc < 0 && rc != -EINTR)
452 cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
461 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
462 struct smb_rqst *rqst, int flags)
465 struct smb2_transform_hdr *tr_hdr;
466 struct smb_rqst cur_rqst[MAX_COMPOUND];
469 if (!(flags & CIFS_TRANSFORM_REQ))
470 return __smb_send_rqst(server, num_rqst, rqst);
472 if (num_rqst > MAX_COMPOUND - 1)
475 if (!server->ops->init_transform_rq) {
476 cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
480 tr_hdr = kmalloc(sizeof(*tr_hdr), GFP_NOFS);
484 memset(&cur_rqst[0], 0, sizeof(cur_rqst));
485 memset(&iov, 0, sizeof(iov));
486 memset(tr_hdr, 0, sizeof(*tr_hdr));
488 iov.iov_base = tr_hdr;
489 iov.iov_len = sizeof(*tr_hdr);
490 cur_rqst[0].rq_iov = &iov;
491 cur_rqst[0].rq_nvec = 1;
493 rc = server->ops->init_transform_rq(server, num_rqst + 1,
498 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
499 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
506 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
507 unsigned int smb_buf_length)
510 struct smb_rqst rqst = { .rq_iov = iov,
513 iov[0].iov_base = smb_buffer;
515 iov[1].iov_base = (char *)smb_buffer + 4;
516 iov[1].iov_len = smb_buf_length;
518 return __smb_send_rqst(server, 1, &rqst);
522 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
523 const int timeout, const int flags,
524 unsigned int *instance)
530 int scredits, in_flight;
533 t = MAX_JIFFY_OFFSET;
535 t = msecs_to_jiffies(timeout);
537 optype = flags & CIFS_OP_MASK;
541 credits = server->ops->get_credits_field(server, optype);
542 /* Since an echo is already inflight, no need to wait to send another */
543 if (*credits <= 0 && optype == CIFS_ECHO_OP)
546 spin_lock(&server->req_lock);
547 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
548 /* oplock breaks must not be held up */
550 if (server->in_flight > server->max_in_flight)
551 server->max_in_flight = server->in_flight;
553 *instance = server->reconnect_instance;
555 in_flight = server->in_flight;
556 spin_unlock(&server->req_lock);
558 trace_smb3_add_credits(server->CurrentMid,
559 server->conn_id, server->hostname, scredits, -1, in_flight);
560 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
561 __func__, 1, scredits);
567 if (*credits < num_credits) {
569 spin_unlock(&server->req_lock);
571 cifs_num_waiters_inc(server);
572 rc = wait_event_killable_timeout(server->request_q,
573 has_credits(server, credits, num_credits), t);
574 cifs_num_waiters_dec(server);
576 spin_lock(&server->req_lock);
578 in_flight = server->in_flight;
579 spin_unlock(&server->req_lock);
581 trace_smb3_credit_timeout(server->CurrentMid,
582 server->conn_id, server->hostname, scredits,
583 num_credits, in_flight);
584 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
588 if (rc == -ERESTARTSYS)
590 spin_lock(&server->req_lock);
592 if (server->tcpStatus == CifsExiting) {
593 spin_unlock(&server->req_lock);
598 * For normal commands, reserve the last MAX_COMPOUND
599 * credits to compound requests.
600 * Otherwise these compounds could be permanently
601 * starved for credits by single-credit requests.
603 * To prevent spinning CPU, block this thread until
604 * there are >MAX_COMPOUND credits available.
605 * But only do this is we already have a lot of
606 * credits in flight to avoid triggering this check
607 * for servers that are slow to hand out credits on
610 if (!optype && num_credits == 1 &&
611 server->in_flight > 2 * MAX_COMPOUND &&
612 *credits <= MAX_COMPOUND) {
613 spin_unlock(&server->req_lock);
615 cifs_num_waiters_inc(server);
616 rc = wait_event_killable_timeout(
618 has_credits(server, credits,
621 cifs_num_waiters_dec(server);
623 spin_lock(&server->req_lock);
625 in_flight = server->in_flight;
626 spin_unlock(&server->req_lock);
628 trace_smb3_credit_timeout(
630 server->conn_id, server->hostname,
631 scredits, num_credits, in_flight);
632 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
636 if (rc == -ERESTARTSYS)
638 spin_lock(&server->req_lock);
643 * Can not count locking commands against total
644 * as they are allowed to block on server.
647 /* update # of requests on the wire to server */
648 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
649 *credits -= num_credits;
650 server->in_flight += num_credits;
651 if (server->in_flight > server->max_in_flight)
652 server->max_in_flight = server->in_flight;
653 *instance = server->reconnect_instance;
656 in_flight = server->in_flight;
657 spin_unlock(&server->req_lock);
659 trace_smb3_add_credits(server->CurrentMid,
660 server->conn_id, server->hostname, scredits,
661 -(num_credits), in_flight);
662 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
663 __func__, num_credits, scredits);
671 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
672 unsigned int *instance)
674 return wait_for_free_credits(server, 1, -1, flags,
679 wait_for_compound_request(struct TCP_Server_Info *server, int num,
680 const int flags, unsigned int *instance)
683 int scredits, in_flight;
685 credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
687 spin_lock(&server->req_lock);
689 in_flight = server->in_flight;
691 if (*credits < num) {
693 * If the server is tight on resources or just gives us less
694 * credits for other reasons (e.g. requests are coming out of
695 * order and the server delays granting more credits until it
696 * processes a missing mid) and we exhausted most available
697 * credits there may be situations when we try to send
698 * a compound request but we don't have enough credits. At this
699 * point the client needs to decide if it should wait for
700 * additional credits or fail the request. If at least one
701 * request is in flight there is a high probability that the
702 * server will return enough credits to satisfy this compound
705 * Return immediately if no requests in flight since we will be
706 * stuck on waiting for credits.
708 if (server->in_flight == 0) {
709 spin_unlock(&server->req_lock);
710 trace_smb3_insufficient_credits(server->CurrentMid,
711 server->conn_id, server->hostname, scredits,
713 cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n",
714 __func__, in_flight, num, scredits);
718 spin_unlock(&server->req_lock);
720 return wait_for_free_credits(server, num, 60000, flags,
725 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
726 unsigned int *num, struct cifs_credits *credits)
730 credits->instance = server->reconnect_instance;
734 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
735 struct mid_q_entry **ppmidQ)
737 if (ses->server->tcpStatus == CifsExiting) {
741 if (ses->server->tcpStatus == CifsNeedReconnect) {
742 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
746 if (ses->status == CifsNew) {
747 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
748 (in_buf->Command != SMB_COM_NEGOTIATE))
750 /* else ok - we are setting up session */
753 if (ses->status == CifsExiting) {
754 /* check if SMB session is bad because we are setting it up */
755 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
757 /* else ok - we are shutting down session */
760 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
763 spin_lock(&GlobalMid_Lock);
764 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
765 spin_unlock(&GlobalMid_Lock);
770 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
774 error = wait_event_freezekillable_unsafe(server->response_q,
775 midQ->mid_state != MID_REQUEST_SUBMITTED);
783 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
786 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
787 struct mid_q_entry *mid;
789 if (rqst->rq_iov[0].iov_len != 4 ||
790 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
791 return ERR_PTR(-EIO);
793 /* enable signing if server requires it */
795 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
797 mid = AllocMidQEntry(hdr, server);
799 return ERR_PTR(-ENOMEM);
801 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
803 DeleteMidQEntry(mid);
811 * Send a SMB request and set the callback function in the mid to handle
812 * the result. Caller is responsible for dealing with timeouts.
815 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
816 mid_receive_t *receive, mid_callback_t *callback,
817 mid_handle_t *handle, void *cbdata, const int flags,
818 const struct cifs_credits *exist_credits)
821 struct mid_q_entry *mid;
822 struct cifs_credits credits = { .value = 0, .instance = 0 };
823 unsigned int instance;
826 optype = flags & CIFS_OP_MASK;
828 if ((flags & CIFS_HAS_CREDITS) == 0) {
829 rc = wait_for_free_request(server, flags, &instance);
833 credits.instance = instance;
835 instance = exist_credits->instance;
837 mutex_lock(&server->srv_mutex);
840 * We can't use credits obtained from the previous session to send this
841 * request. Check if there were reconnects after we obtained credits and
842 * return -EAGAIN in such cases to let callers handle it.
844 if (instance != server->reconnect_instance) {
845 mutex_unlock(&server->srv_mutex);
846 add_credits_and_wake_if(server, &credits, optype);
850 mid = server->ops->setup_async_request(server, rqst);
852 mutex_unlock(&server->srv_mutex);
853 add_credits_and_wake_if(server, &credits, optype);
857 mid->receive = receive;
858 mid->callback = callback;
859 mid->callback_data = cbdata;
860 mid->handle = handle;
861 mid->mid_state = MID_REQUEST_SUBMITTED;
863 /* put it on the pending_mid_q */
864 spin_lock(&GlobalMid_Lock);
865 list_add_tail(&mid->qhead, &server->pending_mid_q);
866 spin_unlock(&GlobalMid_Lock);
869 * Need to store the time in mid before calling I/O. For call_async,
870 * I/O response may come back and free the mid entry on another thread.
872 cifs_save_when_sent(mid);
873 cifs_in_send_inc(server);
874 rc = smb_send_rqst(server, 1, rqst, flags);
875 cifs_in_send_dec(server);
878 revert_current_mid(server, mid->credits);
879 server->sequence_number -= 2;
880 cifs_delete_mid(mid);
883 mutex_unlock(&server->srv_mutex);
888 add_credits_and_wake_if(server, &credits, optype);
894 * Send an SMB Request. No response info (other than return code)
895 * needs to be parsed.
897 * flags indicate the type of request buffer and how long to wait
898 * and whether to log NT STATUS code (error) before mapping it to POSIX error
902 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
903 char *in_buf, int flags)
910 iov[0].iov_base = in_buf;
911 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
912 flags |= CIFS_NO_RSP_BUF;
913 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
914 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
920 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
924 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
925 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
927 spin_lock(&GlobalMid_Lock);
928 switch (mid->mid_state) {
929 case MID_RESPONSE_RECEIVED:
930 spin_unlock(&GlobalMid_Lock);
932 case MID_RETRY_NEEDED:
935 case MID_RESPONSE_MALFORMED:
942 if (!(mid->mid_flags & MID_DELETED)) {
943 list_del_init(&mid->qhead);
944 mid->mid_flags |= MID_DELETED;
946 cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
947 __func__, mid->mid, mid->mid_state);
950 spin_unlock(&GlobalMid_Lock);
952 DeleteMidQEntry(mid);
957 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
958 struct mid_q_entry *mid)
960 return server->ops->send_cancel ?
961 server->ops->send_cancel(server, rqst, mid) : 0;
965 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
968 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
970 dump_smb(mid->resp_buf, min_t(u32, 92, len));
972 /* convert the length into a more usable form */
976 struct smb_rqst rqst = { .rq_iov = iov,
979 iov[0].iov_base = mid->resp_buf;
981 iov[1].iov_base = (char *)mid->resp_buf + 4;
982 iov[1].iov_len = len - 4;
983 /* FIXME: add code to kill session */
984 rc = cifs_verify_signature(&rqst, server,
985 mid->sequence_number);
987 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
991 /* BB special case reconnect tid and uid here? */
992 return map_and_check_smb_error(mid, log_error);
996 cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
997 struct smb_rqst *rqst)
1000 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
1001 struct mid_q_entry *mid;
1003 if (rqst->rq_iov[0].iov_len != 4 ||
1004 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
1005 return ERR_PTR(-EIO);
1007 rc = allocate_mid(ses, hdr, &mid);
1010 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
1012 cifs_delete_mid(mid);
1019 cifs_compound_callback(struct mid_q_entry *mid)
1021 struct TCP_Server_Info *server = mid->server;
1022 struct cifs_credits credits;
1024 credits.value = server->ops->get_credits(mid);
1025 credits.instance = server->reconnect_instance;
1027 add_credits(server, &credits, mid->optype);
1031 cifs_compound_last_callback(struct mid_q_entry *mid)
1033 cifs_compound_callback(mid);
1034 cifs_wake_up_task(mid);
1038 cifs_cancelled_callback(struct mid_q_entry *mid)
1040 cifs_compound_callback(mid);
1041 DeleteMidQEntry(mid);
1045 * Return a channel (master if none) of @ses that can be used to send
1048 * If we are currently binding a new channel (negprot/sess.setup),
1049 * return the new incomplete channel.
1051 struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
1058 if (!ses->binding) {
1060 if (ses->chan_count > 1) {
1061 index = (uint)atomic_inc_return(&ses->chan_seq);
1062 index %= ses->chan_count;
1064 return ses->chans[index].server;
1066 return cifs_ses_server(ses);
1071 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
1072 struct TCP_Server_Info *server,
1073 const int flags, const int num_rqst, struct smb_rqst *rqst,
1074 int *resp_buf_type, struct kvec *resp_iov)
1076 int i, j, optype, rc = 0;
1077 struct mid_q_entry *midQ[MAX_COMPOUND];
1078 bool cancelled_mid[MAX_COMPOUND] = {false};
1079 struct cifs_credits credits[MAX_COMPOUND] = {
1080 { .value = 0, .instance = 0 }
1082 unsigned int instance;
1085 optype = flags & CIFS_OP_MASK;
1087 for (i = 0; i < num_rqst; i++)
1088 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
1090 if (!ses || !ses->server || !server) {
1091 cifs_dbg(VFS, "Null session\n");
1095 if (server->tcpStatus == CifsExiting)
1099 * Wait for all the requests to become available.
1100 * This approach still leaves the possibility to be stuck waiting for
1101 * credits if the server doesn't grant credits to the outstanding
1102 * requests and if the client is completely idle, not generating any
1104 * This can be handled by the eventual session reconnect.
1106 rc = wait_for_compound_request(server, num_rqst, flags,
1111 for (i = 0; i < num_rqst; i++) {
1112 credits[i].value = 1;
1113 credits[i].instance = instance;
1117 * Make sure that we sign in the same order that we send on this socket
1118 * and avoid races inside tcp sendmsg code that could cause corruption
1122 mutex_lock(&server->srv_mutex);
1125 * All the parts of the compound chain belong obtained credits from the
1126 * same session. We can not use credits obtained from the previous
1127 * session to send this request. Check if there were reconnects after
1128 * we obtained credits and return -EAGAIN in such cases to let callers
1131 if (instance != server->reconnect_instance) {
1132 mutex_unlock(&server->srv_mutex);
1133 for (j = 0; j < num_rqst; j++)
1134 add_credits(server, &credits[j], optype);
1138 for (i = 0; i < num_rqst; i++) {
1139 midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
1140 if (IS_ERR(midQ[i])) {
1141 revert_current_mid(server, i);
1142 for (j = 0; j < i; j++)
1143 cifs_delete_mid(midQ[j]);
1144 mutex_unlock(&server->srv_mutex);
1146 /* Update # of requests on wire to server */
1147 for (j = 0; j < num_rqst; j++)
1148 add_credits(server, &credits[j], optype);
1149 return PTR_ERR(midQ[i]);
1152 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1153 midQ[i]->optype = optype;
1155 * Invoke callback for every part of the compound chain
1156 * to calculate credits properly. Wake up this thread only when
1157 * the last element is received.
1159 if (i < num_rqst - 1)
1160 midQ[i]->callback = cifs_compound_callback;
1162 midQ[i]->callback = cifs_compound_last_callback;
1164 cifs_in_send_inc(server);
1165 rc = smb_send_rqst(server, num_rqst, rqst, flags);
1166 cifs_in_send_dec(server);
1168 for (i = 0; i < num_rqst; i++)
1169 cifs_save_when_sent(midQ[i]);
1172 revert_current_mid(server, num_rqst);
1173 server->sequence_number -= 2;
1176 mutex_unlock(&server->srv_mutex);
1179 * If sending failed for some reason or it is an oplock break that we
1180 * will not receive a response to - return credits back
1182 if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
1183 for (i = 0; i < num_rqst; i++)
1184 add_credits(server, &credits[i], optype);
1189 * At this point the request is passed to the network stack - we assume
1190 * that any credits taken from the server structure on the client have
1191 * been spent and we can't return them back. Once we receive responses
1192 * we will collect credits granted by the server in the mid callbacks
1193 * and add those credits to the server structure.
1197 * Compounding is never used during session establish.
1199 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP))
1200 smb311_update_preauth_hash(ses, rqst[0].rq_iov,
1203 for (i = 0; i < num_rqst; i++) {
1204 rc = wait_for_response(server, midQ[i]);
1209 for (; i < num_rqst; i++) {
1210 cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
1211 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1212 send_cancel(server, &rqst[i], midQ[i]);
1213 spin_lock(&GlobalMid_Lock);
1214 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1215 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
1216 midQ[i]->callback = cifs_cancelled_callback;
1217 cancelled_mid[i] = true;
1218 credits[i].value = 0;
1220 spin_unlock(&GlobalMid_Lock);
1224 for (i = 0; i < num_rqst; i++) {
1228 rc = cifs_sync_mid_result(midQ[i], server);
1230 /* mark this mid as cancelled to not free it below */
1231 cancelled_mid[i] = true;
1235 if (!midQ[i]->resp_buf ||
1236 midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
1238 cifs_dbg(FYI, "Bad MID state?\n");
1242 buf = (char *)midQ[i]->resp_buf;
1243 resp_iov[i].iov_base = buf;
1244 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1245 server->vals->header_preamble_size;
1247 if (midQ[i]->large_buf)
1248 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1250 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1252 rc = server->ops->check_receive(midQ[i], server,
1253 flags & CIFS_LOG_ERROR);
1255 /* mark it so buf will not be freed by cifs_delete_mid */
1256 if ((flags & CIFS_NO_RSP_BUF) == 0)
1257 midQ[i]->resp_buf = NULL;
1262 * Compounding is never used during session establish.
1264 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1266 .iov_base = resp_iov[0].iov_base,
1267 .iov_len = resp_iov[0].iov_len
1269 smb311_update_preauth_hash(ses, &iov, 1);
1274 * This will dequeue all mids. After this it is important that the
1275 * demultiplex_thread will not process any of these mids any futher.
1276 * This is prevented above by using a noop callback that will not
1277 * wake this thread except for the very last PDU.
1279 for (i = 0; i < num_rqst; i++) {
1280 if (!cancelled_mid[i])
1281 cifs_delete_mid(midQ[i]);
1288 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1289 struct TCP_Server_Info *server,
1290 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1291 struct kvec *resp_iov)
1293 return compound_send_recv(xid, ses, server, flags, 1,
1294 rqst, resp_buf_type, resp_iov);
1298 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1299 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1300 const int flags, struct kvec *resp_iov)
1302 struct smb_rqst rqst;
1303 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1306 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1307 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1310 /* otherwise cifs_send_recv below sets resp_buf_type */
1311 *resp_buf_type = CIFS_NO_BUFFER;
1317 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1318 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1320 new_iov[0].iov_base = new_iov[1].iov_base;
1321 new_iov[0].iov_len = 4;
1322 new_iov[1].iov_base += 4;
1323 new_iov[1].iov_len -= 4;
1325 memset(&rqst, 0, sizeof(struct smb_rqst));
1326 rqst.rq_iov = new_iov;
1327 rqst.rq_nvec = n_vec + 1;
1329 rc = cifs_send_recv(xid, ses, ses->server,
1330 &rqst, resp_buf_type, flags, resp_iov);
1331 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1337 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1338 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1339 int *pbytes_returned, const int flags)
1342 struct mid_q_entry *midQ;
1343 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1344 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1345 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1346 struct cifs_credits credits = { .value = 1, .instance = 0 };
1347 struct TCP_Server_Info *server;
1350 cifs_dbg(VFS, "Null smb session\n");
1353 server = ses->server;
1354 if (server == NULL) {
1355 cifs_dbg(VFS, "Null tcp session\n");
1359 if (server->tcpStatus == CifsExiting)
1362 /* Ensure that we do not send more than 50 overlapping requests
1363 to the same server. We may make this configurable later or
1366 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1367 cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1372 rc = wait_for_free_request(server, flags, &credits.instance);
1376 /* make sure that we sign in the same order that we send on this socket
1377 and avoid races inside tcp sendmsg code that could cause corruption
1380 mutex_lock(&server->srv_mutex);
1382 rc = allocate_mid(ses, in_buf, &midQ);
1384 mutex_unlock(&server->srv_mutex);
1385 /* Update # of requests on wire to server */
1386 add_credits(server, &credits, 0);
1390 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1392 mutex_unlock(&server->srv_mutex);
1396 midQ->mid_state = MID_REQUEST_SUBMITTED;
1398 cifs_in_send_inc(server);
1399 rc = smb_send(server, in_buf, len);
1400 cifs_in_send_dec(server);
1401 cifs_save_when_sent(midQ);
1404 server->sequence_number -= 2;
1406 mutex_unlock(&server->srv_mutex);
1411 rc = wait_for_response(server, midQ);
1413 send_cancel(server, &rqst, midQ);
1414 spin_lock(&GlobalMid_Lock);
1415 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1416 /* no longer considered to be "in-flight" */
1417 midQ->callback = DeleteMidQEntry;
1418 spin_unlock(&GlobalMid_Lock);
1419 add_credits(server, &credits, 0);
1422 spin_unlock(&GlobalMid_Lock);
1425 rc = cifs_sync_mid_result(midQ, server);
1427 add_credits(server, &credits, 0);
1431 if (!midQ->resp_buf || !out_buf ||
1432 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1434 cifs_server_dbg(VFS, "Bad MID state?\n");
1438 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1439 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1440 rc = cifs_check_receive(midQ, server, 0);
1442 cifs_delete_mid(midQ);
1443 add_credits(server, &credits, 0);
1448 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1449 blocking lock to return. */
1452 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1453 struct smb_hdr *in_buf,
1454 struct smb_hdr *out_buf)
1457 struct cifs_ses *ses = tcon->ses;
1458 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1460 /* We just modify the current in_buf to change
1461 the type of lock from LOCKING_ANDX_SHARED_LOCK
1462 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1463 LOCKING_ANDX_CANCEL_LOCK. */
1465 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1467 pSMB->hdr.Mid = get_next_mid(ses->server);
1469 return SendReceive(xid, ses, in_buf, out_buf,
1470 &bytes_returned, 0);
1474 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1475 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1476 int *pbytes_returned)
1480 struct mid_q_entry *midQ;
1481 struct cifs_ses *ses;
1482 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1483 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1484 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1485 unsigned int instance;
1486 struct TCP_Server_Info *server;
1488 if (tcon == NULL || tcon->ses == NULL) {
1489 cifs_dbg(VFS, "Null smb session\n");
1493 server = ses->server;
1495 if (server == NULL) {
1496 cifs_dbg(VFS, "Null tcp session\n");
1500 if (server->tcpStatus == CifsExiting)
1503 /* Ensure that we do not send more than 50 overlapping requests
1504 to the same server. We may make this configurable later or
1507 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1508 cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1513 rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
1517 /* make sure that we sign in the same order that we send on this socket
1518 and avoid races inside tcp sendmsg code that could cause corruption
1521 mutex_lock(&server->srv_mutex);
1523 rc = allocate_mid(ses, in_buf, &midQ);
1525 mutex_unlock(&server->srv_mutex);
1529 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1531 cifs_delete_mid(midQ);
1532 mutex_unlock(&server->srv_mutex);
1536 midQ->mid_state = MID_REQUEST_SUBMITTED;
1537 cifs_in_send_inc(server);
1538 rc = smb_send(server, in_buf, len);
1539 cifs_in_send_dec(server);
1540 cifs_save_when_sent(midQ);
1543 server->sequence_number -= 2;
1545 mutex_unlock(&server->srv_mutex);
1548 cifs_delete_mid(midQ);
1552 /* Wait for a reply - allow signals to interrupt. */
1553 rc = wait_event_interruptible(server->response_q,
1554 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1555 ((server->tcpStatus != CifsGood) &&
1556 (server->tcpStatus != CifsNew)));
1558 /* Were we interrupted by a signal ? */
1559 if ((rc == -ERESTARTSYS) &&
1560 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1561 ((server->tcpStatus == CifsGood) ||
1562 (server->tcpStatus == CifsNew))) {
1564 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1565 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1566 blocking lock to return. */
1567 rc = send_cancel(server, &rqst, midQ);
1569 cifs_delete_mid(midQ);
1573 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1574 to cause the blocking lock to return. */
1576 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1578 /* If we get -ENOLCK back the lock may have
1579 already been removed. Don't exit in this case. */
1580 if (rc && rc != -ENOLCK) {
1581 cifs_delete_mid(midQ);
1586 rc = wait_for_response(server, midQ);
1588 send_cancel(server, &rqst, midQ);
1589 spin_lock(&GlobalMid_Lock);
1590 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1591 /* no longer considered to be "in-flight" */
1592 midQ->callback = DeleteMidQEntry;
1593 spin_unlock(&GlobalMid_Lock);
1596 spin_unlock(&GlobalMid_Lock);
1599 /* We got the response - restart system call. */
1603 rc = cifs_sync_mid_result(midQ, server);
1607 /* rcvd frame is ok */
1608 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1610 cifs_tcon_dbg(VFS, "Bad MID state?\n");
1614 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1615 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1616 rc = cifs_check_receive(midQ, server, 0);
1618 cifs_delete_mid(midQ);
1619 if (rstart && rc == -EACCES)
1620 return -ERESTARTSYS;